drivers/pci/hotplug/shpchp_ctrl.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Standard Hot Plug Controller Driver
  *
  * Copyright (C) 1995,2001 Compaq Computer Corporation
  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
  * Copyright (C) 2001 IBM Corp.
  * Copyright (C) 2003-2004 Intel Corporation
  *
  * All rights reserved.
  *
  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
  *
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/pci.h>
 #include "../pci.h"
 #include "shpchp.h"

 static void interrupt_event_handler(struct work_struct *work);
 static int shpchp_enable_slot(struct slot *p_slot);
 static int shpchp_disable_slot(struct slot *p_slot);

 static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
 {
 	struct event_info *info;

 	info = kmalloc(sizeof(*info), GFP_ATOMIC);
 	if (!info)
 		return -ENOMEM;

 	info->event_type = event_type;
 	info->p_slot = p_slot;
 	INIT_WORK(&info->work, interrupt_event_handler);

 	queue_work(p_slot->wq, &info->work);

 	return 0;
 }

 u8 shpchp_handle_attention_button(u8 hp_slot, struct controller *ctrl)
 {
 	struct slot *p_slot;
 	u32 event_type;

 	/* Attention Button Change */
 	ctrl_dbg(ctrl, "Attention button interrupt received\n");

 	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
 	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));

 	/*
 	 *  Button pressed - See if need to TAKE ACTION!!!
 	 */
 	ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
 	event_type = INT_BUTTON_PRESS;

 	queue_interrupt_event(p_slot, event_type);

 	return 0;

 }

 u8 shpchp_handle_switch_change(u8 hp_slot, struct controller *ctrl)
 {
 	struct slot *p_slot;
 	u8 getstatus;
 	u32 event_type;

 	/* Switch Change */
 	ctrl_dbg(ctrl, "Switch interrupt received\n");

 	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
 	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
 	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 	ctrl_dbg(ctrl, "Card present %x Power status %x\n",
 		 p_slot->presence_save, p_slot->pwr_save);

 	if (getstatus) {
 		/*
 		 * Switch opened
 		 */
 		ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
 		event_type = INT_SWITCH_OPEN;
 		if (p_slot->pwr_save && p_slot->presence_save) {
 			event_type = INT_POWER_FAULT;
 			ctrl_err(ctrl, "Surprise Removal of card\n");
 		}
 	} else {
 		/*
 		 *  Switch closed
 		 */
 		ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
 		event_type = INT_SWITCH_CLOSE;
 	}

 	queue_interrupt_event(p_slot, event_type);

 	return 1;
 }

 u8 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl)
 {
 	struct slot *p_slot;
 	u32 event_type;

 	/* Presence Change */
 	ctrl_dbg(ctrl, "Presence/Notify input change\n");

 	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

 	/*
 	 * Save the presence state
 	 */
 	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
 	if (p_slot->presence_save) {
 		/*
 		 * Card Present
 		 */
 		ctrl_info(ctrl, "Card present on Slot(%s)\n",
 			  slot_name(p_slot));
 		event_type = INT_PRESENCE_ON;
 	} else {
 		/*
 		 * Not Present
 		 */
 		ctrl_info(ctrl, "Card not present on Slot(%s)\n",
 			  slot_name(p_slot));
 		event_type = INT_PRESENCE_OFF;
 	}

 	queue_interrupt_event(p_slot, event_type);

 	return 1;
 }

 u8 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl)
 {
 	struct slot *p_slot;
 	u32 event_type;

 	/* Power fault */
 	ctrl_dbg(ctrl, "Power fault interrupt received\n");

 	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

 	if (!(p_slot->hpc_ops->query_power_fault(p_slot))) {
 		/*
 		 * Power fault Cleared
 		 */
 		ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
 			  slot_name(p_slot));
 		p_slot->status = 0x00;
 		event_type = INT_POWER_FAULT_CLEAR;
 	} else {
 		/*
 		 *   Power fault
 		 */
 		ctrl_info(ctrl, "Power fault on Slot(%s)\n", slot_name(p_slot));
 		event_type = INT_POWER_FAULT;
 		/* set power fault status for this board */
 		p_slot->status = 0xFF;
 		ctrl_info(ctrl, "Power fault bit %x set\n", hp_slot);
 	}

 	queue_interrupt_event(p_slot, event_type);

 	return 1;
 }

 /* The following routines constitute the bulk of the
    hotplug controller logic
  */
 static int change_bus_speed(struct controller *ctrl, struct slot *p_slot,
 		enum pci_bus_speed speed)
 {
 	int rc = 0;

 	ctrl_dbg(ctrl, "Change speed to %d\n", speed);
 	rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, speed);
 	if (rc) {
 		ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
 			 __func__);
 		return WRONG_BUS_FREQUENCY;
 	}
 	return rc;
 }

 static int fix_bus_speed(struct controller *ctrl, struct slot *pslot,
 		u8 flag, enum pci_bus_speed asp, enum pci_bus_speed bsp,
 		enum pci_bus_speed msp)
 {
 	int rc = 0;

 	/*
 	 * If other slots on the same bus are occupied, we cannot
 	 * change the bus speed.
 	 */
 	if (flag) {
 		if (asp < bsp) {
 			ctrl_err(ctrl, "Speed of bus %x and adapter %x mismatch\n",
 				 bsp, asp);
 			rc = WRONG_BUS_FREQUENCY;
 		}
 		return rc;
 	}

 	if (asp < msp) {
 		if (bsp != asp)
 			rc = change_bus_speed(ctrl, pslot, asp);
 	} else {
 		if (bsp != msp)
 			rc = change_bus_speed(ctrl, pslot, msp);
 	}
 	return rc;
 }

 /**
  * board_added - Called after a board has been added to the system.
  * @p_slot: target &slot
  *
  * Turns power on for the board.
  * Configures board.
  */
 static int board_added(struct slot *p_slot)
 {
 	u8 hp_slot;
 	u8 slots_not_empty = 0;
 	int rc = 0;
 	enum pci_bus_speed asp, bsp, msp;
 	struct controller *ctrl = p_slot->ctrl;
 	struct pci_bus *parent = ctrl->pci_dev->subordinate;

 	hp_slot = p_slot->device - ctrl->slot_device_offset;

 	ctrl_dbg(ctrl, "%s: p_slot->device, slot_offset, hp_slot = %d, %d ,%d\n",
 		 __func__, p_slot->device, ctrl->slot_device_offset, hp_slot);

 	/* Power on slot without connecting to bus */
 	rc = p_slot->hpc_ops->power_on_slot(p_slot);
 	if (rc) {
 		ctrl_err(ctrl, "Failed to power on slot\n");
 		return -1;
 	}

 	if ((ctrl->pci_dev->vendor == 0x8086) && (ctrl->pci_dev->device == 0x0332)) {
 		rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, PCI_SPEED_33MHz);
 		if (rc) {
 			ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
 				 __func__);
 			return WRONG_BUS_FREQUENCY;
 		}

 		/* turn on board, blink green LED, turn off Amber LED */
 		rc = p_slot->hpc_ops->slot_enable(p_slot);
 		if (rc) {
 			ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
 			return rc;
 		}
 	}

 	rc = p_slot->hpc_ops->get_adapter_speed(p_slot, &asp);
 	if (rc) {
 		ctrl_err(ctrl, "Can't get adapter speed or bus mode mismatch\n");
 		return WRONG_BUS_FREQUENCY;
 	}

 	bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
 	msp = ctrl->pci_dev->subordinate->max_bus_speed;

 	/* Check if there are other slots or devices on the same bus */
 	if (!list_empty(&ctrl->pci_dev->subordinate->devices))
 		slots_not_empty = 1;

 	ctrl_dbg(ctrl, "%s: slots_not_empty %d, adapter_speed %d, bus_speed %d, max_bus_speed %d\n",
 		 __func__, slots_not_empty, asp,
 		 bsp, msp);

 	rc = fix_bus_speed(ctrl, p_slot, slots_not_empty, asp, bsp, msp);
 	if (rc)
 		return rc;

 	/* turn on board, blink green LED, turn off Amber LED */
 	rc = p_slot->hpc_ops->slot_enable(p_slot);
 	if (rc) {
 		ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
 		return rc;
 	}

 	/* Wait for ~1 second */
 	msleep(1000);

 	ctrl_dbg(ctrl, "%s: slot status = %x\n", __func__, p_slot->status);
 	/* Check for a power fault */
 	if (p_slot->status == 0xFF) {
 		/* power fault occurred, but it was benign */
 		ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
 		rc = POWER_FAILURE;
 		p_slot->status = 0;
 		goto err_exit;
 	}

 	if (shpchp_configure_device(p_slot)) {
 		ctrl_err(ctrl, "Cannot add device at %04x:%02x:%02x\n",
 			 pci_domain_nr(parent), p_slot->bus, p_slot->device);
 		goto err_exit;
 	}

 	p_slot->status = 0;
 	p_slot->is_a_board = 0x01;
 	p_slot->pwr_save = 1;

 	p_slot->hpc_ops->green_led_on(p_slot);

 	return 0;

 err_exit:
 	/* turn off slot, turn on Amber LED, turn off Green LED */
 	rc = p_slot->hpc_ops->slot_disable(p_slot);
 	if (rc) {
 		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
 			 __func__);
 		return rc;
 	}

 	return(rc);
 }


 /**
  * remove_board - Turns off slot and LEDs
  * @p_slot: target &slot
  */
 static int remove_board(struct slot *p_slot)
 {
 	struct controller *ctrl = p_slot->ctrl;
 	u8 hp_slot;
 	int rc;

 	if (shpchp_unconfigure_device(p_slot))
 		return(1);

 	hp_slot = p_slot->device - ctrl->slot_device_offset;
 	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

 	ctrl_dbg(ctrl, "%s: hp_slot = %d\n", __func__, hp_slot);

 	/* Change status to shutdown */
 	if (p_slot->is_a_board)
 		p_slot->status = 0x01;

 	/* turn off slot, turn on Amber LED, turn off Green LED */
 	rc = p_slot->hpc_ops->slot_disable(p_slot);
 	if (rc) {
 		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
 			 __func__);
 		return rc;
 	}

 	rc = p_slot->hpc_ops->set_attention_status(p_slot, 0);
 	if (rc) {
 		ctrl_err(ctrl, "Issue of Set Attention command failed\n");
 		return rc;
 	}

 	p_slot->pwr_save = 0;
 	p_slot->is_a_board = 0;

 	return 0;
 }


 struct pushbutton_work_info {
 	struct slot *p_slot;
 	struct work_struct work;
 };

 /**
  * shpchp_pushbutton_thread - handle pushbutton events
  * @work: &struct work_struct to be handled
  *
  * Scheduled procedure to handle blocking stuff for the pushbuttons.
  * Handles all pending events and exits.
  */
 static void shpchp_pushbutton_thread(struct work_struct *work)
 {
 	struct pushbutton_work_info *info =
 		container_of(work, struct pushbutton_work_info, work);
 	struct slot *p_slot = info->p_slot;

 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
 	case POWEROFF_STATE:
 		mutex_unlock(&p_slot->lock);
 		shpchp_disable_slot(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;
 	case POWERON_STATE:
 		mutex_unlock(&p_slot->lock);
 		if (shpchp_enable_slot(p_slot))
 			p_slot->hpc_ops->green_led_off(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;
 	default:
 		break;
 	}
 	mutex_unlock(&p_slot->lock);

 	kfree(info);
 }

 void shpchp_queue_pushbutton_work(struct work_struct *work)
 {
 	struct slot *p_slot = container_of(work, struct slot, work.work);
 	struct pushbutton_work_info *info;

 	info = kmalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
 			 __func__);
 		return;
 	}
 	info->p_slot = p_slot;
 	INIT_WORK(&info->work, shpchp_pushbutton_thread);

 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
 	case BLINKINGOFF_STATE:
 		p_slot->state = POWEROFF_STATE;
 		break;
 	case BLINKINGON_STATE:
 		p_slot->state = POWERON_STATE;
 		break;
 	default:
 		kfree(info);
 		goto out;
 	}
 	queue_work(p_slot->wq, &info->work);
  out:
 	mutex_unlock(&p_slot->lock);
 }

 static void update_slot_info(struct slot *slot)
 {
 	slot->hpc_ops->get_power_status(slot, &slot->pwr_save);
 	slot->hpc_ops->get_attention_status(slot, &slot->attention_save);
 	slot->hpc_ops->get_latch_status(slot, &slot->latch_save);
 	slot->hpc_ops->get_adapter_status(slot, &slot->presence_save);
 }

 /*
  * Note: This function must be called with slot->lock held
  */
 static void handle_button_press_event(struct slot *p_slot)
 {
 	u8 getstatus;
 	struct controller *ctrl = p_slot->ctrl;

 	switch (p_slot->state) {
 	case STATIC_STATE:
 		p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
 		if (getstatus) {
 			p_slot->state = BLINKINGOFF_STATE;
 			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
 				  slot_name(p_slot));
 		} else {
 			p_slot->state = BLINKINGON_STATE;
 			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
 				  slot_name(p_slot));
 		}
 		/* blink green LED and turn off amber */
 		p_slot->hpc_ops->green_led_blink(p_slot);
 		p_slot->hpc_ops->set_attention_status(p_slot, 0);

 		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
 		break;
 	case BLINKINGOFF_STATE:
 	case BLINKINGON_STATE:
 		/*
 		 * Cancel if we are still blinking; this means that we
 		 * press the attention again before the 5 sec. limit
 		 * expires to cancel hot-add or hot-remove
 		 */
 		ctrl_info(ctrl, "Button cancel on Slot(%s)\n",
 			  slot_name(p_slot));
 		cancel_delayed_work(&p_slot->work);
 		if (p_slot->state == BLINKINGOFF_STATE)
 			p_slot->hpc_ops->green_led_on(p_slot);
 		else
 			p_slot->hpc_ops->green_led_off(p_slot);
 		p_slot->hpc_ops->set_attention_status(p_slot, 0);
 		ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
 			  slot_name(p_slot));
 		p_slot->state = STATIC_STATE;
 		break;
 	case POWEROFF_STATE:
 	case POWERON_STATE:
 		/*
 		 * Ignore if the slot is on power-on or power-off state;
 		 * this means that the previous attention button action
 		 * to hot-add or hot-remove is undergoing
 		 */
 		ctrl_info(ctrl, "Button ignore on Slot(%s)\n",
 			  slot_name(p_slot));
 		update_slot_info(p_slot);
 		break;
 	default:
 		ctrl_warn(ctrl, "Not a valid state\n");
 		break;
 	}
 }

 static void interrupt_event_handler(struct work_struct *work)
 {
 	struct event_info *info = container_of(work, struct event_info, work);
 	struct slot *p_slot = info->p_slot;

 	mutex_lock(&p_slot->lock);
 	switch (info->event_type) {
 	case INT_BUTTON_PRESS:
 		handle_button_press_event(p_slot);
 		break;
 	case INT_POWER_FAULT:
 		ctrl_dbg(p_slot->ctrl, "%s: Power fault\n", __func__);
 		p_slot->hpc_ops->set_attention_status(p_slot, 1);
 		p_slot->hpc_ops->green_led_off(p_slot);
 		break;
 	default:
 		update_slot_info(p_slot);
 		break;
 	}
 	mutex_unlock(&p_slot->lock);

 	kfree(info);
 }


 static int shpchp_enable_slot (struct slot *p_slot)
 {
 	u8 getstatus = 0;
 	int rc, retval = -ENODEV;
 	struct controller *ctrl = p_slot->ctrl;

 	/* Check to see if (latch closed, card present, power off) */
 	mutex_lock(&p_slot->ctrl->crit_sect);
 	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
 	if (rc || !getstatus) {
 		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
 		goto out;
 	}
 	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 	if (rc || getstatus) {
 		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
 		goto out;
 	}
 	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
 	if (rc || getstatus) {
 		ctrl_info(ctrl, "Already enabled on slot(%s)\n",
 			  slot_name(p_slot));
 		goto out;
 	}

 	p_slot->is_a_board = 1;

 	/* We have to save the presence info for these slots */
 	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
 	p_slot->hpc_ops->get_power_status(p_slot, &(p_slot->pwr_save));
 	ctrl_dbg(ctrl, "%s: p_slot->pwr_save %x\n", __func__, p_slot->pwr_save);
 	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

 	if ((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD &&
 	     p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458)
 	     && p_slot->ctrl->num_slots == 1) {
 		/* handle AMD POGO errata; this must be done before enable  */
 		amd_pogo_errata_save_misc_reg(p_slot);
 		retval = board_added(p_slot);
 		/* handle AMD POGO errata; this must be done after enable  */
 		amd_pogo_errata_restore_misc_reg(p_slot);
 	} else
 		retval = board_added(p_slot);

 	if (retval) {
 		p_slot->hpc_ops->get_adapter_status(p_slot,
 				&(p_slot->presence_save));
 		p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 	}

 	update_slot_info(p_slot);
  out:
 	mutex_unlock(&p_slot->ctrl->crit_sect);
 	return retval;
 }


 static int shpchp_disable_slot (struct slot *p_slot)
 {
 	u8 getstatus = 0;
 	int rc, retval = -ENODEV;
 	struct controller *ctrl = p_slot->ctrl;

 	if (!p_slot->ctrl)
 		return -ENODEV;

 	/* Check to see if (latch closed, card present, power on) */
 	mutex_lock(&p_slot->ctrl->crit_sect);

 	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
 	if (rc || !getstatus) {
 		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
 		goto out;
 	}
 	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 	if (rc || getstatus) {
 		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
 		goto out;
 	}
 	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
 	if (rc || !getstatus) {
 		ctrl_info(ctrl, "Already disabled on slot(%s)\n",
 			  slot_name(p_slot));
 		goto out;
 	}

 	retval = remove_board(p_slot);
 	update_slot_info(p_slot);
  out:
 	mutex_unlock(&p_slot->ctrl->crit_sect);
 	return retval;
 }

 int shpchp_sysfs_enable_slot(struct slot *p_slot)
 {
 	int retval = -ENODEV;
 	struct controller *ctrl = p_slot->ctrl;

 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
 	case BLINKINGON_STATE:
 		cancel_delayed_work(&p_slot->work);
 		/* fall through */
 	case STATIC_STATE:
 		p_slot->state = POWERON_STATE;
 		mutex_unlock(&p_slot->lock);
 		retval = shpchp_enable_slot(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;
 	case POWERON_STATE:
 		ctrl_info(ctrl, "Slot %s is already in powering on state\n",
 			  slot_name(p_slot));
 		break;
 	case BLINKINGOFF_STATE:
 	case POWEROFF_STATE:
 		ctrl_info(ctrl, "Already enabled on slot %s\n",
 			  slot_name(p_slot));
 		break;
 	default:
 		ctrl_err(ctrl, "Not a valid state on slot %s\n",
 			 slot_name(p_slot));
 		break;
 	}
 	mutex_unlock(&p_slot->lock);

 	return retval;
 }

 int shpchp_sysfs_disable_slot(struct slot *p_slot)
 {
 	int retval = -ENODEV;
 	struct controller *ctrl = p_slot->ctrl;

 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
 	case BLINKINGOFF_STATE:
 		cancel_delayed_work(&p_slot->work);
 		/* fall through */
 	case STATIC_STATE:
 		p_slot->state = POWEROFF_STATE;
 		mutex_unlock(&p_slot->lock);
 		retval = shpchp_disable_slot(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;
 	case POWEROFF_STATE:
 		ctrl_info(ctrl, "Slot %s is already in powering off state\n",
 			  slot_name(p_slot));
 		break;
 	case BLINKINGON_STATE:
 	case POWERON_STATE:
 		ctrl_info(ctrl, "Already disabled on slot %s\n",
 			  slot_name(p_slot));
 		break;
 	default:
 		ctrl_err(ctrl, "Not a valid state on slot %s\n",
 			 slot_name(p_slot));
 		break;
 	}
 	mutex_unlock(&p_slot->lock);

 	return retval;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Standard Hot Plug Controller Driver
	*
	* Copyright (C) 1995,2001 Compaq Computer Corporation
	* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
	* Copyright (C) 2001 IBM Corp.
	* Copyright (C) 2003-2004 Intel Corporation
	*
	* All rights reserved.
	*
	* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
	*
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/pci.h>
	#include "../pci.h"
	#include "shpchp.h"

	static void interrupt_event_handler(struct work_struct *work);
	static int shpchp_enable_slot(struct slot *p_slot);
	static int shpchp_disable_slot(struct slot *p_slot);

	static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
	{
	struct event_info *info;

	info = kmalloc(sizeof(*info), GFP_ATOMIC);
	if (!info)
	return -ENOMEM;

	info->event_type = event_type;
	info->p_slot = p_slot;
	INIT_WORK(&info->work, interrupt_event_handler);

	queue_work(p_slot->wq, &info->work);

	return 0;
	}

	u8 shpchp_handle_attention_button(u8 hp_slot, struct controller *ctrl)
	{
	struct slot *p_slot;
	u32 event_type;

	/* Attention Button Change */
	ctrl_dbg(ctrl, "Attention button interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));

	/*
	* Button pressed - See if need to TAKE ACTION!!!
	*/
	ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
	event_type = INT_BUTTON_PRESS;

	queue_interrupt_event(p_slot, event_type);

	return 0;

	}

	u8 shpchp_handle_switch_change(u8 hp_slot, struct controller *ctrl)
	{
	struct slot *p_slot;
	u8 getstatus;
	u32 event_type;

	/* Switch Change */
	ctrl_dbg(ctrl, "Switch interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
	ctrl_dbg(ctrl, "Card present %x Power status %x\n",
	p_slot->presence_save, p_slot->pwr_save);

	if (getstatus) {
	/*
	* Switch opened
	*/
	ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
	event_type = INT_SWITCH_OPEN;
	if (p_slot->pwr_save && p_slot->presence_save) {
	event_type = INT_POWER_FAULT;
	ctrl_err(ctrl, "Surprise Removal of card\n");
	}
	} else {
	/*
	* Switch closed
	*/
	ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
	event_type = INT_SWITCH_CLOSE;
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
	}

	u8 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl)
	{
	struct slot *p_slot;
	u32 event_type;

	/* Presence Change */
	ctrl_dbg(ctrl, "Presence/Notify input change\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	/*
	* Save the presence state
	*/
	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
	if (p_slot->presence_save) {
	/*
	* Card Present
	*/
	ctrl_info(ctrl, "Card present on Slot(%s)\n",
	slot_name(p_slot));
	event_type = INT_PRESENCE_ON;
	} else {
	/*
	* Not Present
	*/
	ctrl_info(ctrl, "Card not present on Slot(%s)\n",
	slot_name(p_slot));
	event_type = INT_PRESENCE_OFF;
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
	}

	u8 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl)
	{
	struct slot *p_slot;
	u32 event_type;

	/* Power fault */
	ctrl_dbg(ctrl, "Power fault interrupt received\n");

	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	if (!(p_slot->hpc_ops->query_power_fault(p_slot))) {
	/*
	* Power fault Cleared
	*/
	ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
	slot_name(p_slot));
	p_slot->status = 0x00;
	event_type = INT_POWER_FAULT_CLEAR;
	} else {
	/*
	* Power fault
	*/
	ctrl_info(ctrl, "Power fault on Slot(%s)\n", slot_name(p_slot));
	event_type = INT_POWER_FAULT;
	/* set power fault status for this board */
	p_slot->status = 0xFF;
	ctrl_info(ctrl, "Power fault bit %x set\n", hp_slot);
	}

	queue_interrupt_event(p_slot, event_type);

	return 1;
	}

	/* The following routines constitute the bulk of the
	hotplug controller logic
	*/
	static int change_bus_speed(struct controller ctrl, struct slot p_slot,
	enum pci_bus_speed speed)
	{
	int rc = 0;

	ctrl_dbg(ctrl, "Change speed to %d\n", speed);
	rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, speed);
	if (rc) {
	ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
	__func__);
	return WRONG_BUS_FREQUENCY;
	}
	return rc;
	}

	static int fix_bus_speed(struct controller ctrl, struct slot pslot,
	u8 flag, enum pci_bus_speed asp, enum pci_bus_speed bsp,
	enum pci_bus_speed msp)
	{
	int rc = 0;

	/*
	* If other slots on the same bus are occupied, we cannot
	* change the bus speed.
	*/
	if (flag) {
	if (asp < bsp) {
	ctrl_err(ctrl, "Speed of bus %x and adapter %x mismatch\n",
	bsp, asp);
	rc = WRONG_BUS_FREQUENCY;
	}
	return rc;
	}

	if (asp < msp) {
	if (bsp != asp)
	rc = change_bus_speed(ctrl, pslot, asp);
	} else {
	if (bsp != msp)
	rc = change_bus_speed(ctrl, pslot, msp);
	}
	return rc;
	}

	/**
	* board_added - Called after a board has been added to the system.
	* @p_slot: target &slot
	*
	* Turns power on for the board.
	* Configures board.
	*/
	static int board_added(struct slot *p_slot)
	{
	u8 hp_slot;
	u8 slots_not_empty = 0;
	int rc = 0;
	enum pci_bus_speed asp, bsp, msp;
	struct controller *ctrl = p_slot->ctrl;
	struct pci_bus *parent = ctrl->pci_dev->subordinate;

	hp_slot = p_slot->device - ctrl->slot_device_offset;

	ctrl_dbg(ctrl, "%s: p_slot->device, slot_offset, hp_slot = %d, %d ,%d\n",
	__func__, p_slot->device, ctrl->slot_device_offset, hp_slot);

	/* Power on slot without connecting to bus */
	rc = p_slot->hpc_ops->power_on_slot(p_slot);
	if (rc) {
	ctrl_err(ctrl, "Failed to power on slot\n");
	return -1;
	}

	if ((ctrl->pci_dev->vendor == 0x8086) && (ctrl->pci_dev->device == 0x0332)) {
	rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, PCI_SPEED_33MHz);
	if (rc) {
	ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
	__func__);
	return WRONG_BUS_FREQUENCY;
	}

	/* turn on board, blink green LED, turn off Amber LED */
	rc = p_slot->hpc_ops->slot_enable(p_slot);
	if (rc) {
	ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
	return rc;
	}
	}

	rc = p_slot->hpc_ops->get_adapter_speed(p_slot, &asp);
	if (rc) {
	ctrl_err(ctrl, "Can't get adapter speed or bus mode mismatch\n");
	return WRONG_BUS_FREQUENCY;
	}

	bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
	msp = ctrl->pci_dev->subordinate->max_bus_speed;

	/* Check if there are other slots or devices on the same bus */
	if (!list_empty(&ctrl->pci_dev->subordinate->devices))
	slots_not_empty = 1;

	ctrl_dbg(ctrl, "%s: slots_not_empty %d, adapter_speed %d, bus_speed %d, max_bus_speed %d\n",
	__func__, slots_not_empty, asp,
	bsp, msp);

	rc = fix_bus_speed(ctrl, p_slot, slots_not_empty, asp, bsp, msp);
	if (rc)
	return rc;

	/* turn on board, blink green LED, turn off Amber LED */
	rc = p_slot->hpc_ops->slot_enable(p_slot);
	if (rc) {
	ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
	return rc;
	}

	/* Wait for ~1 second */
	msleep(1000);

	ctrl_dbg(ctrl, "%s: slot status = %x\n", __func__, p_slot->status);
	/* Check for a power fault */
	if (p_slot->status == 0xFF) {
	/* power fault occurred, but it was benign */
	ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
	rc = POWER_FAILURE;
	p_slot->status = 0;
	goto err_exit;
	}

	if (shpchp_configure_device(p_slot)) {
	ctrl_err(ctrl, "Cannot add device at %04x:%02x:%02x\n",
	pci_domain_nr(parent), p_slot->bus, p_slot->device);
	goto err_exit;
	}

	p_slot->status = 0;
	p_slot->is_a_board = 0x01;
	p_slot->pwr_save = 1;

	p_slot->hpc_ops->green_led_on(p_slot);

	return 0;

	err_exit:
	/* turn off slot, turn on Amber LED, turn off Green LED */
	rc = p_slot->hpc_ops->slot_disable(p_slot);
	if (rc) {
	ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
	__func__);
	return rc;
	}

	return(rc);
	}


	/**
	* remove_board - Turns off slot and LEDs
	* @p_slot: target &slot
	*/
	static int remove_board(struct slot *p_slot)
	{
	struct controller *ctrl = p_slot->ctrl;
	u8 hp_slot;
	int rc;

	if (shpchp_unconfigure_device(p_slot))
	return(1);

	hp_slot = p_slot->device - ctrl->slot_device_offset;
	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);

	ctrl_dbg(ctrl, "%s: hp_slot = %d\n", __func__, hp_slot);

	/* Change status to shutdown */
	if (p_slot->is_a_board)
	p_slot->status = 0x01;

	/* turn off slot, turn on Amber LED, turn off Green LED */
	rc = p_slot->hpc_ops->slot_disable(p_slot);
	if (rc) {
	ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
	__func__);
	return rc;
	}

	rc = p_slot->hpc_ops->set_attention_status(p_slot, 0);
	if (rc) {
	ctrl_err(ctrl, "Issue of Set Attention command failed\n");
	return rc;
	}

	p_slot->pwr_save = 0;
	p_slot->is_a_board = 0;

	return 0;
	}


	struct pushbutton_work_info {
	struct slot *p_slot;
	struct work_struct work;
	};

	/**
	* shpchp_pushbutton_thread - handle pushbutton events
	* @work: &struct work_struct to be handled
	*
	* Scheduled procedure to handle blocking stuff for the pushbuttons.
	* Handles all pending events and exits.
	*/
	static void shpchp_pushbutton_thread(struct work_struct *work)
	{
	struct pushbutton_work_info *info =
	container_of(work, struct pushbutton_work_info, work);
	struct slot *p_slot = info->p_slot;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case POWEROFF_STATE:
	mutex_unlock(&p_slot->lock);
	shpchp_disable_slot(p_slot);
	mutex_lock(&p_slot->lock);
	p_slot->state = STATIC_STATE;
	break;
	case POWERON_STATE:
	mutex_unlock(&p_slot->lock);
	if (shpchp_enable_slot(p_slot))
	p_slot->hpc_ops->green_led_off(p_slot);
	mutex_lock(&p_slot->lock);
	p_slot->state = STATIC_STATE;
	break;
	default:
	break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
	}

	void shpchp_queue_pushbutton_work(struct work_struct *work)
	{
	struct slot *p_slot = container_of(work, struct slot, work.work);
	struct pushbutton_work_info *info;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
	ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
	__func__);
	return;
	}
	info->p_slot = p_slot;
	INIT_WORK(&info->work, shpchp_pushbutton_thread);

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
	p_slot->state = POWEROFF_STATE;
	break;
	case BLINKINGON_STATE:
	p_slot->state = POWERON_STATE;
	break;
	default:
	kfree(info);
	goto out;
	}
	queue_work(p_slot->wq, &info->work);
	out:
	mutex_unlock(&p_slot->lock);
	}

	static void update_slot_info(struct slot *slot)
	{
	slot->hpc_ops->get_power_status(slot, &slot->pwr_save);
	slot->hpc_ops->get_attention_status(slot, &slot->attention_save);
	slot->hpc_ops->get_latch_status(slot, &slot->latch_save);
	slot->hpc_ops->get_adapter_status(slot, &slot->presence_save);
	}

	/*
	* Note: This function must be called with slot->lock held
	*/
	static void handle_button_press_event(struct slot *p_slot)
	{
	u8 getstatus;
	struct controller *ctrl = p_slot->ctrl;

	switch (p_slot->state) {
	case STATIC_STATE:
	p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
	if (getstatus) {
	p_slot->state = BLINKINGOFF_STATE;
	ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
	slot_name(p_slot));
	} else {
	p_slot->state = BLINKINGON_STATE;
	ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
	slot_name(p_slot));
	}
	/* blink green LED and turn off amber */
	p_slot->hpc_ops->green_led_blink(p_slot);
	p_slot->hpc_ops->set_attention_status(p_slot, 0);

	queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
	break;
	case BLINKINGOFF_STATE:
	case BLINKINGON_STATE:
	/*
	* Cancel if we are still blinking; this means that we
	* press the attention again before the 5 sec. limit
	* expires to cancel hot-add or hot-remove
	*/
	ctrl_info(ctrl, "Button cancel on Slot(%s)\n",
	slot_name(p_slot));
	cancel_delayed_work(&p_slot->work);
	if (p_slot->state == BLINKINGOFF_STATE)
	p_slot->hpc_ops->green_led_on(p_slot);
	else
	p_slot->hpc_ops->green_led_off(p_slot);
	p_slot->hpc_ops->set_attention_status(p_slot, 0);
	ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
	slot_name(p_slot));
	p_slot->state = STATIC_STATE;
	break;
	case POWEROFF_STATE:
	case POWERON_STATE:
	/*
	* Ignore if the slot is on power-on or power-off state;
	* this means that the previous attention button action
	* to hot-add or hot-remove is undergoing
	*/
	ctrl_info(ctrl, "Button ignore on Slot(%s)\n",
	slot_name(p_slot));
	update_slot_info(p_slot);
	break;
	default:
	ctrl_warn(ctrl, "Not a valid state\n");
	break;
	}
	}

	static void interrupt_event_handler(struct work_struct *work)
	{
	struct event_info *info = container_of(work, struct event_info, work);
	struct slot *p_slot = info->p_slot;

	mutex_lock(&p_slot->lock);
	switch (info->event_type) {
	case INT_BUTTON_PRESS:
	handle_button_press_event(p_slot);
	break;
	case INT_POWER_FAULT:
	ctrl_dbg(p_slot->ctrl, "%s: Power fault\n", __func__);
	p_slot->hpc_ops->set_attention_status(p_slot, 1);
	p_slot->hpc_ops->green_led_off(p_slot);
	break;
	default:
	update_slot_info(p_slot);
	break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
	}


	static int shpchp_enable_slot (struct slot *p_slot)
	{
	u8 getstatus = 0;
	int rc, retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	/* Check to see if (latch closed, card present, power off) */
	mutex_lock(&p_slot->ctrl->crit_sect);
	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
	if (rc \|\| !getstatus) {
	ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
	goto out;
	}
	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
	if (rc \|\| getstatus) {
	ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
	goto out;
	}
	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
	if (rc \|\| getstatus) {
	ctrl_info(ctrl, "Already enabled on slot(%s)\n",
	slot_name(p_slot));
	goto out;
	}

	p_slot->is_a_board = 1;

	/* We have to save the presence info for these slots */
	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
	p_slot->hpc_ops->get_power_status(p_slot, &(p_slot->pwr_save));
	ctrl_dbg(ctrl, "%s: p_slot->pwr_save %x\n", __func__, p_slot->pwr_save);
	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);

	if ((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD &&
	p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458)
	&& p_slot->ctrl->num_slots == 1) {
	/* handle AMD POGO errata; this must be done before enable */
	amd_pogo_errata_save_misc_reg(p_slot);
	retval = board_added(p_slot);
	/* handle AMD POGO errata; this must be done after enable */
	amd_pogo_errata_restore_misc_reg(p_slot);
	} else
	retval = board_added(p_slot);

	if (retval) {
	p_slot->hpc_ops->get_adapter_status(p_slot,
	&(p_slot->presence_save));
	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
	}

	update_slot_info(p_slot);
	out:
	mutex_unlock(&p_slot->ctrl->crit_sect);
	return retval;
	}


	static int shpchp_disable_slot (struct slot *p_slot)
	{
	u8 getstatus = 0;
	int rc, retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	if (!p_slot->ctrl)
	return -ENODEV;

	/* Check to see if (latch closed, card present, power on) */
	mutex_lock(&p_slot->ctrl->crit_sect);

	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
	if (rc \|\| !getstatus) {
	ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
	goto out;
	}
	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
	if (rc \|\| getstatus) {
	ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
	goto out;
	}
	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
	if (rc \|\| !getstatus) {
	ctrl_info(ctrl, "Already disabled on slot(%s)\n",
	slot_name(p_slot));
	goto out;
	}

	retval = remove_board(p_slot);
	update_slot_info(p_slot);
	out:
	mutex_unlock(&p_slot->ctrl->crit_sect);
	return retval;
	}

	int shpchp_sysfs_enable_slot(struct slot *p_slot)
	{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGON_STATE:
	cancel_delayed_work(&p_slot->work);
	/* fall through */
	case STATIC_STATE:
	p_slot->state = POWERON_STATE;
	mutex_unlock(&p_slot->lock);
	retval = shpchp_enable_slot(p_slot);
	mutex_lock(&p_slot->lock);
	p_slot->state = STATIC_STATE;
	break;
	case POWERON_STATE:
	ctrl_info(ctrl, "Slot %s is already in powering on state\n",
	slot_name(p_slot));
	break;
	case BLINKINGOFF_STATE:
	case POWEROFF_STATE:
	ctrl_info(ctrl, "Already enabled on slot %s\n",
	slot_name(p_slot));
	break;
	default:
	ctrl_err(ctrl, "Not a valid state on slot %s\n",
	slot_name(p_slot));
	break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
	}

	int shpchp_sysfs_disable_slot(struct slot *p_slot)
	{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
	cancel_delayed_work(&p_slot->work);
	/* fall through */
	case STATIC_STATE:
	p_slot->state = POWEROFF_STATE;
	mutex_unlock(&p_slot->lock);
	retval = shpchp_disable_slot(p_slot);
	mutex_lock(&p_slot->lock);
	p_slot->state = STATIC_STATE;
	break;
	case POWEROFF_STATE:
	ctrl_info(ctrl, "Slot %s is already in powering off state\n",
	slot_name(p_slot));
	break;
	case BLINKINGON_STATE:
	case POWERON_STATE:
	ctrl_info(ctrl, "Already disabled on slot %s\n",
	slot_name(p_slot));
	break;
	default:
	ctrl_err(ctrl, "Not a valid state on slot %s\n",
	slot_name(p_slot));
	break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
	}